Reduction of the lithium and nickel site substitution in Li1+xNi0.5Co0.2Mn0.3O2 with Li excess as a cathode electrode material for Li-ion batteries

Layered Li1+xNi0.5Co0.2Mn0.3O2 (x = 0, 0.02, 0.04, 0.06, 0.08) materials were synthesized using the co-precipitation method. Rietveld refinements measurements reveal that the concentration of Ni2+-3b ions decreases from 0.06 to 0.043, with x changing from 0.02 to 0.08. The initial coulombic efficiency improves with the increase in the content of Li-excess because the content of Ni at the 3b site decreases with the increase of Li-excess in the samples from 0 to 0.08. The analysis indicates that Li1.08Ni0.5Co0.2Mn0.3O2 exhibits the largest diffusivity value due to the dependence of the diffusion coefficient of lithium ions on the content of Ni in the 3b sites.